Standards-compliant calculators for plumbers in NZ & Australia. Free, no signup required. Works on mobile.
Each calculator opens on its own page — bookmark the ones you use most.
Check pipe velocity against AS/NZS 3500 limits. Hazen-Williams pressure drop for copper, PVC and PE.
Size storage cylinders (90–400 L) and continuous flow units (kW) for any property.
Calculate roof collection potential and recommend tank size for any NZ/AU location.